Alcohol's Mixed Health Record

Drinking offers health benefits and risks. Get help sifting through the latest findings.

If you’ve read the recent headlines on the health effects of alcohol and are feeling dazed and confused, it’s not just you. Study results published within a single week – or day – suggest a bewildering range of effects for alcohol consumption.

According to some of the most recent studies, alcohol use may prevent Alzheimer’s disease yet it can also cause brain damage. It is linked to stomach and lung cancers but it also seems to improve longevity. What are we to make of these findings, which are seemingly so at odds with one another?

Much the reason that alcohol has different effects in different studies has to do with the amount of drinking the study participants are doing.

In this article we’ll sift through some of the recent data on alcohol consumption, and help sort out how much, and perhaps more importantly, how frequently, alcohol should be consumed to be beneficial rather than detrimental.

Moderation is Part (but Only Part) of the Puzzle

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Some of the answer lies in how drinking is defined. Mild to moderate drinking is generally linked to better health effects, while heavier drinking, particularly in bouts or binges, is more often linked to worse health outcomes.

According to the NIH, “moderate drinking is probably safe.” Though the statement is not exactly a ringing endorsement, it’s the best guess we have as the research continues to come in. The NIH, along with most researchers, defines moderate drinking as one drink per day for women, and two per day for men – tops. For both sexes over the age of 65, drinking should also be limited to one drink or less per day. Problems seem to occur when people drink more than this amount.

Alcohol may stress the brain just enough that it makes brain cells more adaptable to larger stresses that are linked to increased Alzheimer’s risk. On the flip side, drinking too much may stress the brain beyond repair, so that excessive alcohol consumption leads to irreparable damage.

In the last few months, a number of studies have reported results that are generally in line with these recommendations. Much the reason that alcohol has different effects in different studies has to do with the amount of drinking the study participants are doing. An excellent example of this is a large-scale study that recently reported that people who drink moderately, defined as one drink per day for women and two for men, were at reduced risk of any form of cognitive decline, including Alzheimer’s disease.

But heavier drinking was not so good: in fact, the same study found that drinking three to five drinks per day was linked to a greater risk of Alzheimer’s disease and other forms of cognitive impairment.

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The explanation for the findings in this study isn’t completely clear. It may be that alcohol is beneficial up to a point because it improves blood flow to the brain, thereby reducing the risk for cognitive problems. Or, according to the researchers, alcohol may stress the brain just enough that it makes brain cells more adaptable to larger stresses that are linked to increased Alzheimer’s risk. On the flip side, drinking too much may stress the brain beyond repair, so that excessive alcohol consumption leads to irreparable damage.

Though the mechanism is not clear, the effect is clear: moderate drinking was linked to benefits, while excessive drinking was linked to risks.

Another recent study confirms the ill effects of the overconsumption of alcohol on the brain, reporting that people who had previously abused alcohol (but were now sober) had damage to certain areas of the brain, compared people who didn’t drink at all. This finding is particularly sobering in that it illustrates alcohol’s serious long term effects on the brain, even after abstinence.

Other studies just in have reported that heavy drinking is linked to increased risk of both lung cancer and stomach cancer. These studies taken together, suggest that there is a critical line between healthy and unhealthy drinking, which is not surprisingly tied to the amount of drinking you do.

With Alcohol, Timing is Everything

While one’s level of alcohol consumption is clearly an integral part of the equation, how you drink also affects how alcohol affects your health. For example, drinking one drink per day over the course of a week might lead to health benefits. But abstaining all week and then having seven drinks on one particular evening can have quite the opposite effect. A new study illustrates this phenomenon nicely.

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The LDL or “bad” cholesterol levels of the “daily-moderate” group dropped by 40% on average. In the weekend-binge group, the average LDL level rose by 20%.

Researchers had mice consume the equivalent of two drinks per day every day (these mice were “daily-moderate” drinkers) or seven drinks per day on two days of the week (the “weekend-binge” group). The team looked at markers of heart and blood vessel health to determine what effect the different patterns of alcohol use had on cardiovascular health.

The LDL or “bad” cholesterol levels of the “daily-moderate” group dropped by 40% on average. In the weekend-binge group, the average LDL level rose by 20%. Even more, when the researchers looked at other markers of heart health, like the amount of plaque buildup in the animals’ arteries, inflammation, and weight gain, the daily-moderate drinkers were in significantly better shape than the weekend-bingers.

These results illustrate that timing may matter as much as quantity. Again, the reason for this is unclear, but it may be that excessive drinking on one or two days per week stresses the body in significant ways, which can build up over time.

Alcohol and Breast Cancer

Many studies on the health benefits and risks of alcohol include both sexes, and moderate drinking seems to benefit women as much as it does men over the long term. One study found that women who were moderate drinkers in middle age tended to have fewer health problems in older age than women who did not drink at all. In this as with other studies, drinking small to moderate amounts of alcohol routinely had a greater health benefit than drinking sporadically.

Women who drank about two glasses per day – but remember, this is twice the recommended amount – had a 51% increased risk of developing breast cancer.

On the other hand, alcohol poses some unique risks for women because of the ways in which it can affect estrogen. Women who drink may be at increased risk for breast cancer. In another recent study following over 100,000 women, those who drank the equivalent of three to six drinks per week had a slightly increased risk for developing breast cancer (15% higher) than women who abstained or rarely drank. Women who drank about two glasses per day – but remember, this is twice the recommended amount – had a 51% increased risk of developing breast cancer.

It’s important to keep in mind that the increase in breast cancer was “modest,” according to lead author of the study, Wendy Chen, in a news release. Part of the reason for the increased risk for women is that alcohol may raise estrogen levels in the body. Estrogen is known to increase the risk for certain types of breast cancer, which could explain the study’s results.

There is no failsafe rule when it comes to alcohol, particularly for women. Though it may lead to benefits in certain areas, breast cancer is a serious concern, particularly for women who are already at higher risk due to family histories or genetics. Women may want to be cautious about daily drinking, but it is wise to speak with your doctor to discuss all the pros and cons. In general, staying at or below the recommended limits (one glass per day) gives the best chance of enjoying the benefits without experiencing the risks.

Alcohol is More than the Sum of Its Parts

A final piece of information to keep in mind when looking at the latest studies on alcohol is that sometimes only specific ingredients in alcohol are studied. A team reported that supplements containing the antioxidant resveratrol (a powerful polyphenol compound in grapes and wine) improved the metabolism of overweight men. According to the researchers, the effects of resveratrol mimicked the effects of a low-calorie diet in the changes it produced. However, the men were taking supplements that were the equivalent of drinking two gallons of wine per day. Drinking this much wine per day would, of course, not be so good for one’s health.

Whether the amount of the amount of antioxidants in a responsible amount of wine would lead to any noticeable changes in the body – metabolic or otherwise – is still unclear. For this reason, it’s important to remember that studies such as this one point to the possibility of taking supplements that contain the antioxidants found in wine, rather than increasing one’s intake of wine to reap similar benefits.

Whether the amount of the amount of antioxidants in a responsible amount of wine would lead to any noticeable changes in the body – metabolic or otherwise – is still unclear.

The way this type of study may be presented can lead to confusion about whether alcohol itself is good or whether it’s the individual components (often in extraordinarily high quantities) that are beneficial. Alcohol comes with a lot of risks, both physical and psychological, so again, staying at or below the recommended amounts – and talking to your doctor about trying antioxidant supplements if you are curious – is truly the best rule of thumb.

The Bottom Line: No Need to Start

Based on the evidence, a little drinking probably won’t hurt and may even benefit health over the long run. Drinking a little bit routinely appears to be much better than drinking a lot episodically. But, if you don’t currently drink, it’s probably best not to start. The researchers agree that if you abstain, you should continue that way, since the health benefits are still unclear and the risks can be serious.

Heavy drinking is considered to be anything over the recommended limit – which makes it a very fine line between drinking healthily and drinking heavily.

If you are a woman drinking more than one drink a day or a man having more than two drinks per day – which is considered heavy drinking by the CDC – you should probably cut back. Heavy drinking and binge drinking (defined as more than four drinks in one sitting for women and more than five for men) are both included in “excessive” drinking, which, according to a CDC report, costs the nation $223.5 billion annually. (These costs include lost work and productivity, health care costs, and legal issues like alcohol-related crime.) But what is most important to note here is that heavy drinking is considered to be anything over the recommended limit – which makes it a very fine line between drinking healthily and drinking heavily.

There’s no foolproof way to drink alcohol perfectly safely, but staying at or below the recommended limits is the way to go. And as you read more studies on alcohol consumption, always look at who the participants were, how much and how frequently they were drinking, and whether it was alcohol or supplements containing ingredients from alcohol that the participants consumed. If you are concerned about your drinking, talk to your doctor – and if you don’t currently drink, the experts agree that there’s not much reason to start.